This invention relates to cementing operations in subterranean formations. In particular, this invention relates to system and methods for effectively and efficiently cementing a casing annulus.
It is common in the oil and gas industry to cement casing in well bores. Generally, a well bore is drilled and a casing string is inserted into the well bore. Drilling mud and/or a circulation fluid is circulated through the well bore by casing annulus and the casing inner diameter to flush excess debris from the well. As used herein, the term “circulation fluid”includes all well bore fluids typically found in a well bore prior to cementing a casing in the well bore. Cement composition is then pumped into the annulus between the casing and the well bore. The cement composition can keep the casing in position and prevent hydrocarbons or other fluids or gasses from flowing through the annulus.
In one method used to place the cement composition in the annulus, the cement composition slurry is pumped down the casing inner diameter, out through a casing shoe and/or circulation valve at the bottom of the casing and up through the annulus to its desired location. Once the cement is set, the operator may drill further down hole.
Typically, once the cement is placed in position the operator must give the cement some time to set before drilling further. Moreover, the stability of the cement column is often dependent on the formation properties with the cement giving way in weaker formation zones. Additionally, the cement may not set in place perfectly which may allow hydrocarbons or hydrostatic pressure to leak through the annulus into an area previously isolated by the cement. It is therefore desirable to provide an efficient and effective method of cementing in a subterranean formation.
While embodiments of this disclosure have been depicted and described and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.